Power inverters include circuitry that functions to change direct current (DC) power to alternating current (AC) power. The size, configuration, and control of an inverter may depend on its application. For instance, in a large-scale power system with an AC power grid, a three-phase inverter is typically used to connect a DC power source, such as one or more photovoltaic (PV) panels, to the power grid. In those applications, an oftentimes heavy and expensive transformer is typically used to isolate the PV panel from the AC power source. Removing the transformer may be beneficial in that it reduces the size and expense of the power system, but the lack of isolation can cause a common mode leakage current to form, which can degrade the current provided by the inverter to the power grid or improperly trigger ground fault protection. Similar leakage currents generated at inverters used in other applications can have the same deleterious effects. Different types of inverters may be used to make this connection, including, but not limited to, neutral-point-clamped (NPC) inverters, flying capacitor inverters, and cascaded H-bridge inverters. Each type of inverter may have benefits and drawbacks. For instance, NPC inverters typically have the fewest number of components and can use less expensive components with lower voltage ratings. NPC inverters, however, can experience voltage imbalance problems that can increase the total harmonic distortion (THD) in the output signal. NPC and other types of inverters may also suffer from leakage current that can further degrade the output signal.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.